The jury at Coleraine Crown Court heard that the two brothers, who cannot be named to protect their victims' identities, admitted in a separate court last week to the sexual abuse of their sister.The pair, and a family friend, are on trial for a second week over 56 charges relating to the rape and abuse of the son and daughter of one of the brothers.They deny the allegations, which include charges of gross indecency and child cruelty dating back to the 1990s.On Monday, the jury of six women and six men was told that the brothers had admitted to the separate 27 charges - including attempted rape and gross indecency - against their sister.The offences began in 1972 when she was just four years old.The proceedings in Coleraine Courthouse also included evidence given by the former wife of one of the defendants - the mother of the alleged victims.She told the jury it was only when her marriage broke up that her daughter told her that she and her brother been abused by their father.She said her daughter "confided to me that her father had touched her and made her touch him".The court also heard details from police interviews with the alleged victims' father.Detectives asked him about his relationship with his children.He was said to have told them: "I tried to be a good father, showing them affection ... I would have hugged them. I'm sure I gave them kisses on their heads."The trial had already heard allegations that the man used cigarettes to burn his daughter's body, calling her his "ashtray".A doctor who had examined the alleged victim and found scar tissue on her body also gave evidence to the court on Monday.She could not be definitive about the cause of the injuries, but said that they were consistent with cigarette burns.The trial continues.